A semiconductor device includes an epitaxial layer having a first conductive type, and at least one first semiconductor layer and a second semiconductor layer having a second conductive type. The first semiconductor layer is disposed in the epitaxial layer of a peripheral region, and has an arc portion, and a first strip portion and a second strip portion extended from two ends of the arc portion. The first strip portion points to an active device region, and the second strip portion is perpendicular to the first strip portion The second semiconductor layer is disposed in the epitaxial layer of the peripheral region between the active device region and the second strip portion, and the second semiconductor has a sidewall facing and parallel to the first semiconductor layer.